Apple messed up by showing the iPhoto and GarageBand icons in iCloud settings prematurely last week. Although not a common occurrence, Apple has leaked stuff through iTunes and iCloud metadata in the past, so it wasn’t entirely without precedent.
What I wasn’t expecting was for them to screw up again and leak the entirety of the new icon set on their own site ahead of tomorrow’s announcement.
The icons themselves look promising. All of the iWork icons actually feel like they were made with iOS in mind. The lucid green Numbers is a little rough, though.